Relay



July 5, 1955 J. M. THERIAULT RELAY Filed March 30, 1953 5 12 15 y i 15 i1 12 RELAY .lean Marie Theriault, Montreal, Quebec, Canada Application March 30, 1953, Serial No. 345,632 1 (Ziaim. (Cl. 200106) The present invention pertains to a novel relay intended particularly for use in a fire alarm system.

The principal object of the invention is to provide a relay that energizes an alarm circuit on completion of a thermostat circuit when a given temperature is indicated by the thermostat. Another object is to provide a relay that opens the thermostat circuit when the alarm circuit is energized and yet maintains the alarm circuit.

A further object is to provide manual means for reestablishing the thermostat circuit, so that the alarm circuit may function anew under the critical conditions. Finally, an object is to provide a simple and effective construction for the purposes set forth.

in the accomplishment of these objects, the device comprises an electro-magnet which attracts a soft iron rmature carried by a pivoted plate. A spring attached to one end of the plate normally draws the plate and armature away from the magnet. The other end of the plate is engageable by a spring-pulled slidable dog adapted to hold the plate in its downward position after the magnet has become de-energized on opening of the thermostat circuit. In the downward position, a pair of contacts on the plate close the alarm circuit, and this circuit is maintained by the action of the dog on the plate as set forth.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings in which:

Figure l is an elevation of the device;

Figure 2 is a similar elevation showing a different position of parts;

Fi ure 3 is a plan view;

Figure 4 is an end view; and

Figure 5 is a partial rear View.

Reference to these views will now be made by use of like characters which are employed to designate corresponding parts throughout.

The base of the device is a rectangular plate 1 on which are mounted two upright brackets 2 holding an electro-magnet 3 which has a center core (not shown). At the top of the magnet is fixed under one end of a plate 4-, a soft iron armature piece 5. From the plate 4 depends a lug 6 pivoted at 7 to the upper end of a post it riveted on the base 1. To the other end of the plate 4 is fixed one end of a coil spring 9 having its other end attached to the base 1.

Over the plate 4 extends an inverted U-shaped bridge member 10 of strip metal having its ends riveted to the base 1. The member 10 carries two spaced screws 11 which support a slide 13 slotted at 12 and having one end bent angularly at 14 and the other end also bent at 15 and joined by a coil spring 16 to the member 10. The bent end or dog 14 is oblique to the main portion of the member 10 and is shaped as a quarter circle. It is extended by a piece 17 of insulating material which carries a contact 18. The latter is adapted to be engaged by a blade contact 19 carried by a post 20 mounted on the base 1.

States Patent 0 The plate 4 carries a smaller rectangular plate 21 of insulating material carrying two spaced finger contacts 22 extending downward to engage a common contact 23 (Figure 4), spring mounted on an insulator 24 carried by a metal support 25 attached to the base 1. The contact 23 is apertured at the center in order to slide on a shaft 26 (Figure 5) suspended from the member 24.

A coil spring 27 surrounds the shaft 26 and engages the head 28 of the shaft to move the contact 23 upward until limited by the member 24 as a stop. A corner of the base 1 supports a double contact 29 which serves as a terminal for a conductor 30 extending to the winding of the electro-magnet 3. Another conductor 31 joins the other end of the winding to the contact 18. To the latter is connected a conductor 32, and each of the contacts 22 has a conductor 33 attached thereto. Finally, a conductor 34 extends to the common contact 23.

In the use of the device, let it be assumed that the conductors 30, 31, contact 19 and conductor 32 are in a circuit connected to a thermostat which closes the circuit when a critical temperature is reached or in case of fire or burglary. The two conductors 33 will be connected to the conductor 34 to close a circuit including lamps, a gong, an automatically closing door, alarms, etc.

The normal position of the relay is shown in Figure 1, that is, the contact 18 is not engaged by the blade contact 19 and the soft iron piece 5 is spaced from the crectro-magnet. When the thermostat (not shown) closes the circuit that includes the conductor 30, magnet 22, conductor 31, contact 18, blade 19 and conductor 32, the magnet attracts the member 5, causing the plate 4 to pivot against the action of the spring 9. The free end of the plate 4 trips off the end 14 of the slide 13, and the spring 16 draws the slide to a position in which the end 14 lies over the plate 4 so that the latter cannot pivot, as in Figure 2. The movement of the slide 13 withdraws the contact 18 from the resilient switch blade 19, whereby the thermostat current is interrupted.

The attracted plate 4 brings the contacts 22 into engagement with the contact 23, whereby the conductors 33 are joined to the conductor 34. The alarm circuit thus energized operates instantly and without interruption, since the dog 14 prevents the plate 4 from moving, notwithstanding the spring 9. When the relay has served its purpose, the slide 13 is moved manually against the spring 16, whereby the plate 4 returns to the position shown in Figure l, in which the dog 14 bears against the free end of the plate 4 and is held there by the spring 16. in other words, the end of the plate 4 retains the dog 14 when the magnet 3 is idle.

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claim.

What I claim is:

A relay comprising a base, an electro-magnet thereon, a plate pivotally mounted with respect to said base, and

' extending over said magnet, a soft iron armature carried by said plate and disposed over said magnet and at one side of the pivot point of said plate, a spring connected to said plate, at the other side or said pivot point, to said base and tensioned to space said armature from said magnet, a slide supported from said base and disposed over said plate, a dog extending from said slide over the end of said plate nearer said armature, a spring drawing said dog against said end, said dog engaging with said plate to hold said slide in one position when magnet is deenergized and said slide being biased to move to a second position upon energization of said magnet releasing said dog, a pair of spaced contacts 3 carried by said slide, a Contact engageable by said spaced contacts in the unenergized position of said armature and plate, said dog being shaped to bias said plate toward said magnet.

References Cited in the file of this patent UNITED STATES PATENTS 4 Rennert Oct. 12, Hanst Nov. 26, Smith Dec. 2, Emmerling et a1 July 9, Werner May 15, Smith June 24, Duggan Aug. 13, Dettar Ian. 20, 

